CODEWITHSUNDEEP
c#azureazure-table-storageazure-sdk-.net
user145610
user145610

Reputation: 3035

How to make use of new TableQuery<T> in azure table storage

I'm trying to create a generic method to read only some properties of azure table. TO create this Im making use of TableQuery, but some how im unable to pass Filter condition 

public  IEnumerable<T1> ExecuteQuery<T, T1>(Expression<Func<T,bool>> predicate)
        where T : TableEntity, IDomainData, new()
        where T1 : new()
    {

        Type typeParameterType = typeof(T);
        CloudTable tableReference = tableClient.GetTableReference(typeParameterType.Name);


        var query = new TableQuery<T>()
        {
           FilterString = predicate.Body.ToString(),
           SelectColumns = typeof(T1).GetListOfPropertyNames()
        };
        query = query.Where(predicate).AsTableQuery(); ==> Throws error Object reference error


        return tableReference.ExecuteQuery(query) as List<T1>;

        //return tableReference.ExecuteQuery<T, T1>(query,EntityAdapter.AdapterResolver<T1>);

    }

Is there where to pass Filterstring to TableQuery and execute the TableQuery with azure table instance

Upvotes: 1

Views: 1422

Answers (1)

Veena Udayabhanu - MSFT
Veena Udayabhanu - MSFT

Reputation: 1269

If you are trying to get a subset of properties from the table along with a filter condition, you would have to specify it using the Select and Where clause as follows - 

TableQuery<T> query = new TableQuery<T>().Select(new List<string>() { "prop1", "prop2" }).Where("filter string");
List<T> result = currentTable.ExecuteQuery(query).ToList();

Also, there are helper methods in the storage client library that you can use to construct the filter strings. See TableQuery.GenerateFilterCondition.

Upvotes: 1

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